ACF in AMP pages

Hi everyone

i need to add field in plugin’s amp template (because it doesn’t recognize automatically ACF fields)
In ‘/admin/partials/pagefrog-amp-template-single.php’ in the plugin folder, i manage to add :
echo get_field(‘field_name’);
and it works
but for Repeater Field and Flexible Content Field, i can’t print the value.I mean this seems to work but only with preview link in pagefrog plugin, not with the real /amp/ page(URL).
am I in the wrong template file?
Could you help me with this , pls?

I use this two links:
https://www.advancedcustomfields.com/resources/repeater/
https://www.advancedcustomfields.com/resources/flexible-content/

Thanks